Outer authomorphisms and the Jacobian
K-Theory and Homology
2007-05-23 v1
Abstract
A graphs of rank n (homotopy equivalent to a wedge of n circles) without ``separating edges'' has a canonical n-dimensional compact C^1 manifold thickening. This implies that the canonical homomorphism f:Out(F_n)-> GL(n,Z) is trivial in rational cohomology in the stable range answering a question raised by Hatcher and Vogtmann [6]. Another consequence of the construction is the existence of higher Reidemeister torsion invariants for IOut(F_n)=ker f. These facts were first proved by the first author in [8] using different methods.
Cite
@article{arxiv.math/0502266,
title = {Outer authomorphisms and the Jacobian},
author = {Kiyoshi Igusa and John Klein and E. Bruce Williams},
journal= {arXiv preprint arXiv:math/0502266},
year = {2007}
}
Comments
19 pages, 2 figures